The invention relates to a blind rivet and more particularly to a blind rivet of the type comprising a tubular shell and a mandrel having an elongate stem and an enlarged head, in which the mandrel stem is used to pull the mandrel head into the shell to radially expand the latter, to form a blind head, and then breaks off to leave the mandrel head plugging the bore of the shell. A blind rivet of this type is hereinafter referred to as "a blind rivet of the type defined".